question regarding macros

[Cristian Coarfa]

Hi,

    I am trying to preprocess the following code with gcc-3.3




#define EXPAND2(pred, args) \
   EXPAND3(pred, handler, args)

#define EXPAND3(pred, handler, args) \
((pred) ? \
  1 :  \
 (handler ## args))

result = EXPAND2( predicate, (arg1, arg2, arg3));


What I am trying to achieve is

result = ((predicate) ? 1 : (handler (arg1, arg2, arg3)));


This produces a warning with gcc-3.2.2, but produces the desired result. 
The warning is:

 pasting "handler" and "(" does not give a valid preprocessing token

gcc 3.3 gives the same message, but produces an error instead.


Are these macros standard conformant, and if not, how do I make them so ?

Thanks,
Cristian